Powers:from Wikipedia:
Galactus wields the immeasurable Power Cosmic and is one of the most powerful entities within the Marvel Universe; he has even been described as "the most powerful creature in the universe." As such, Galactus is able to employ the limitless cosmic energies within him to produce nearly any effect he desires.

Galactus has displayed a vast array of abilities at his command, which include: size-alteration, the molecular restructuring, conversion and transmutation of matter, the projection of energy with incalculable concussive force or heat, the teleportation of objects — even entire galaxies — across space and even time, the erection of impenetrable energy-screens and force fields, the creation of interdimensional and intradimensional portals and wormholes, virtually unlimited telepathic and telekinetic ability, and cosmic awareness on a universal scale. Galactus has even shown the ability to create sentient life, resurrect the dead, manipulate mortal souls, and remake dead worlds — including their populations — in every detail.

Even Galactus' heralds, whom he has endowed with a minuscule fraction of his awesome power, are able to manipulate matter and energy in ways far beyond human comprehension. Indeed, Galactus is so powerful he must always wear his armor to help him regulate his internal energies or else they could run rampant with the potential to change him into a star.

Since Galactus must continuously feed to sustain his energies, his power levels are inconsistent throughout any given period of time. When Galactus' hunger has been recently sated, his powers at the very least rival those possessed by the Celestials. A fully satiated Galactus however, as explained in the Secret Wars saga, has universal awareness and power levels that are on par with those of Eternity himself, though it should be noted that Galactus is almost never satiated to full capacity. As such, the longer Galactus goes without feeding, the more his strength, power and universal awareness wane. Within just one month of consuming a suitable planet Galactus' power reduces exponentially-yet even in such a depleted state his powers are still far beyond human comprehension. Going several months between feedings, as he has done on a few occasions in recent years, can bring him to the brink of death and leave him so weakened that he proves vulnerable to direct assaults from superhuman teams such as the Shi'Ar Imperial Guard, Avengers and the Fantastic Four.

In the universe's earlier years, Galactus could go without feeding for a century before his hunger substantially weakened him. It is currently unknown why the intervals between his feedings have decreased over millennia.

As the oldest known living entity in the universe, Galactus possesses arguably the most advanced intellect of all lifeforms in the cosmos. Over the eons and epochs of his existence, Galactus has amassed cosmic knowledge of such universal depth that there is little knowledge that he does not possess. He is aware of every event of cosmic importance, and being an inherent part of the universe, has often and repeatedly confronted entities and events that would comprimise the existence of the universe as he knows it.

Galactus has created and employed perhaps the most advanced technology ever developed. His constructs are of such sophisticated design and engineering that they often replicate some of his inherent abilities, such as intra and inter-dimensional travel and the transmutation of matter on a massive scale. While the capabilities of other beings, such as the Celestials, are widely regarded as one of the most highly evolved and advanced technologies in the cosmos, the sheer scope and magnitude of Galactus' works are unmatched. The Ultimate Nullifier, itself an aspect of Galactus, endows the user with the power to effectively "nullify" anything and everything within the user's ability to conceptualize. Taa II, the home of Galactus, is of such immense size that its expanse encompasses an entire solar system. Indeed, so astounding is Taa II that Reed Richards--considered to be the most brilliant man on Earth--stated that he could spend the entirety of his life studying just one of the rudimentary machines installed by Galactus.

Weaknesses:It can be argued that with such staggering might and vast intellect, Galactus is prone to over-confidence and underestimation of his foes, as he has often been defeated by lesser beings.

Bio:Rebirth
Originally named Galan of the planet Taa, Galactus is the sole survivor of the Big Crunch of the universe that existed prior to the current Marvel Universe.

Galan was a space explorer investigating the impending end of his universe. His original intent was to discover a means to protect his planet from radiation that was destroying all life in the universe, but he was unable to do so. Eventually, most of Taa was engulfed and rendered dead. As Galan approached the Cosmic Egg, the focal point of the Big Crunch and the source of the life-destroying radiation, his ship and crew were promptly destroyed. At the moment Galan's universe met its end, the incarnation of that reality's Phoenix Force amassed the positive emotions of all living beings in the cosmos to preserve them from eternal damnation, enabling the Sentience of the Universe — the previous universe's incarnation of Eternity — to meet with Galan. Within the Cosmic Egg the Sentience of the Universe revealed itself to Galan and informed him that though they both would die in the impending cataclysm, they would survive through a joint heir born into the next universe. The Sentience of the Universe then merged itself with the mortal Galan, establishing Galan as the sole survivor of the ensuing Big Crunch. This union ultimately led to his rebirth in the current universe as Galactus.

After the Big Bang of the current universe, to complete his metamorphosis, Galactus was encased in a cocoon of enormous cosmic energies. After millions of years, he emerged as an entity of vast cosmic power who was also necessary for the existence of the newly formed universe.

Galactus is considered one of the five essential entities within the Marvel Universe alongside Eternity, Death, Infinity, and Oblivion. Galactus has been referred to as the "third force of the universe" and "one corner of that great triangle which is the universe" by Eternity and Death, respectively. Eternity and Death each consider Galactus a peer and a sibling, with Death actually referring to Galactus as "husband, father, brother, and son."

The Devourer of Worlds
Galactus requires unknown energies obtainable only from certain types of planets in order to sustain his life. The suitable type of planet need not be one where life is present, but it must have the potential to support life. Galactus usually employs a herald to scout the universe for those suitable types of planets. When the suitable planet is found, Galactus will usually land on the planet's surface and assemble his Elemental Converter, a colossal machine capable of draining all life energy from the planet within minutes. Galactus has been known to devour planets without the aid of his Elemental Converter on occasion, but the device makes the process more efficient. Galactus, seeing himself as a higher being, usually will not avoid a suitable planet simply because it is home to sentient life. Thus, over billions of years he has become one of the most feared beings in the universe, his vast power allowing him to lay waste to innumerable extra-terrestrial civilizations in his quest for sustenance.

Nevertheless, he is not an evil being, but rather a force of nature whose feedings are necessary for survival. It is known that Galactus plays a necessary role in the continuum of the Marvel Universe, bringing balance between the two opposing universal forces of Death and Eternity; who are in essence the Yin and Yang of the Marvel universe. Eternity has stated that the universe would fail, falling into stasis then collapsing without Galactus' presence to balance it. It has been suggested by some that his purpose in the universe is to devour planets that have reached an evolutionary peak, although alternative information suggests that he will create a whole new universe at the end of this one, a universe which will be immeasurably greater than the total of the planets he has devoured; thus giving back far more than he has ever taken.

Heralds
Galactus has appointed a number of entities as his heralds, imbuing them with a minuscule portion of his Power Cosmic and sending them to search for edible worlds. Most of his heralds have either rebelled against him, betrayed him or been cast aside for some reason.

Among his heralds are the Fallen One, Silver Surfer, Terrax, Firelord, Air-Walker, the Air-Walker robot, an Earthwoman named Frankie Raye later known as Nova, Morg, Red Shift, the Asgardian Destroyer armor, Human Torch, and Stardust. Gladiator and Tyrant were possibly heralds.

In the Ultimate Marvel storyline Gah Lak Tus, as he is known in the Ultimate Universe, has used the Ultimate version of the Silver Surfer as a herald as well. The ultimate version of the Vision was built as a warning system for the coming of Gah Lak Tus.

Attempts to Devour the Earth
Galactus has threatened to destroy the Earth on several occasions. On the first, the Fantastic Four (aided by the Watcher Uatu and by Galactus' rebellious herald, the Silver Surfer) defeated him by threatening him with the Ultimate Nullifier. Galactus vowed to never again try to harm the Earth.

Nevertheless, he has returned on several occasions, in one instance weakened enough for the Fantastic Four, the Avengers and Doctor Strange to defeat him. Rather than watch him die of hunger, Mister Fantastic saved him, for which Galactus called him "friend," and vowed Earth need never again fear Galactus, and for which Mr Fantastic was later put on galactic trial by the Shi'Ar.

Temporary Death
In the Galactus: The Devourer limited series (1999-2000), Galactus — starving to death due to his addiction to the life forces of living beings which offer him no sustenance — was seemingly killed after a battle against the united forces of the Silver Surfer, Avengers, Fantastic Four, Jean Grey, Starjammers, the Shi'ar Empire and an armada of other united planets (including even a Kree starship) when his own Elemental Converter was turned against him. He died with an ominous warning that his death would allow a great evil to surface. After his death, Galactus' true form was revealed, that of a sentient star.

That great evil emerged in Fantastic Four Annual 2001 in the form of Abraxas, the universal embodiment of destruction and the antithesis of Eternity. It was revealed that most of the energy that Galactus takes from planets was devoted to keeping him imprisoned. If released, Abraxas would eventually destroy the entire multiverse. Abraxas was defeated only after it was revealed in Fantastic Four (vol. 2) #49 (vol. 1) #478; January 2002) that Galactus was not truly dead but in his incorporeal star form he would be forever unable to rein in his energies and reclaim form. Franklin Richards and Valeria Von Doom pooled their vast, Celestial-level powers and reconstituted Galactus, but permanently burned out their powers in the revival. Once reconstituted, Galactus easily reclaimed the Ultimate Nullifier from Abraxas and Reed Richards used it to remake the multiverse into one in which Abraxas never escaped. It was in this issue that the Ultimate Nullifier was revealed to be an aspect of Galactus himself.

"Rising Storm"
In the 2005 Fantastic Four storyline Rising Storm, Reed Richards built a weapon that was designed to strip Galactus of the Power Cosmic - this was made possible due to input from Johnny Storm who was cosmically aware at the time. Johnny Storm, as Invisible Man - Herald of Galactus, managed to keep Galactus occupied long enough for Reed and Quasar to complete construction of the weapon. The weapon actually succeeded in separating the two aspects that comprise Galactus, thus Galan was freed from the Power Cosmic and reduced to his mortal, humanoid form. In tribute to "the indomitable spirit of the humanoid order", Galan willingly exiled himself into an other-universal realm, with the hope that this act would delay the Power Cosmic in finding him.

This did not last long, however, and as Galactus, he encountered Beta Ray Bill in the Stormbreaker mini-series shortly after. The manner in which the Power Cosmic found Galan and reformed Galactus was never revealed.

Annihilation
In the Annihilation: Silver Surfer miniseries, written by Keith Giffen, it was revealed that Galactus was not always the sole member of the "Cosmic Balance"; it has been suggested that Galactus was but one of several beings similar to himself. Due to differing opinions of the powers they had been blessed with, the Balance all but destroyed itself in civil war, with only three remaining - Galactus the Devourer of Worlds, Tenebrous of the Darkness Between, and Aegis the Lady of All Sorrows. Able to subdue his darker brethren in the first Kyln, Galactus remained the only extant member of the Balance, until the Annihilation Wave ruptured the Crunch, freeing Tenebrous and Aegis. Knowing of their escape, Galactus has augmented the Silver Surfer, who is in his employ as Herald once more, and has stated that Tenebrous and Aegis will move against him, indicating awareness. In Annihilation #1, Tenebrous and Aegis seemingly defeat the Silver Surfer and Galactus. In the subsequent issue, the incapacitated Galactus and Silver Surfer are revealed as captives in Thanos' starship, where Annihilus has tasked Thanos with discovering the secret of the Power Cosmic. Annihilation #3 finds Galactus in an unconscious state, while Thanos has harnessed Galactus' cosmic might to utilize him as a weapon of destruction on a large scale. In Annihilation #4, Thanos attempts to release Galactus from his bonds, as the Titan discovers that Annihilus plans to use Galactus as a cosmic bomb to destroy all life in both the 616-universe and the Negative Zone. As he works to free Galactus, Thanos remarks that he would teleport away once the planet eater was released, as he would not want to be on the receiving end of devourer's wrath. However, Thanos meets an untimely end at the hands of Drax the Destroyer before he can release Galactus.

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